Even I know the killers came from a scouting party of Schnelle Gruppe Knittel, a unit commanded by Sturmbannführer Gustav Knittel. They were part of the 1st SS Panzer Division. They had witnesses (the Langer family) and he and others were already on trial for killing other American captives. I personally don't think it would have been all that hard. The eleven Black Americans weren't even listed as victims at the trials whereas all others were named.